Field of the Invention
The present invention relates to a method of processing a wafer having a plurality of projected dicing lines formed in a grid pattern on its face side and a plurality of devices formed in respective areas demarcated on a face side of the wafer by the projected dicing lines, by dividing the wafer into the individual devices along the projected, dicing lines and covering the individual devices with a resin.
Description of the Related Art
In the semiconductor device fabrication process, a plurality of areas are demarcated on the face side of a substantially disk-shaped semiconductor wafer by a plurality of projected dicing lines arranged in a grid pattern on the face side, and devices such as integrated circuits (ICs), large-scale integration (LSI) circuits, etc. are formed in the demarcated areas. The semiconductor wafer thus processed is cut along the projected dicing lines to divide the areas with the devices formed thereon into individual devices.
In recent years, there have been developed packaging technologies wherein a wafer is divided into individual devices and the individual devices are coated with a resin. One of the packaging technologies is referred to as wafer level chip scale packaging (WLCSP), which is disclosed in Japanese Patent Laid-Open No. 2006-100535.
According to the packaging technology disclosed in Japanese Patent Laid-Open No. 2006-100535, the reverse side of a wafer is coated with a resin, cut grooves which reach the resin are formed from the face side of the wafer along projected dicing lines, and a molding resin is laid on the face side of the wafer, covering devices thereon. After the molding resin has been embedded in the cut grooves, the molding resin that has filled the cut grooves is cut by a cutting blade having a thickness smaller than the width of the cut grooves, dividing the wafer into individual package devices referred to as WLCSP.
A technology, to be described below step by step, has been developed as a method of processing a wafer to manufacture package devices referred to as WLCSP.
(1) Cut grooves having a depth corresponding to the finished thickness of devices are formed in a wafer from its face side along projected dicing lines;
(2) A molding resin is laid on the face side of the wafer, and embedded in the cut grooves;
(3) A protective member is applied to the face side of the molding resin laid on the face side of the wafer, and the reverse side of the wafer is ground until the cut grooves are exposed; and
(4) The reverse side of the wafer is applied to a dicing tape, and the molding resin embedded in the cut grooves is cut by a cutting blade having a thickness smaller than the width of the cut grooves, dividing the wafer into individual package devices referred to as WLCSP.